It has come to our attention that the Academic Editor who handled this manuscript, Dr Jim van Os, has co-authored several publications with one of the authors over the last five years.
In line with the PLOS ONE competing interests policy (http://www.plosone.org/st...), we consider this as a potential conflict of interest. Dr van Os was invited by PLOS ONE to act as Academic Editor for this manuscript and we acknowledge that the journal should not have approached him to handle this manuscript.
We have therefore asked an independent Academic Editor, Professor Michel Botbol, to carefully evaluate the peer review process of this article. Professor Botbol has confirmed that he is satisfied that the decision for publication was adequate.
